Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial

Ann Intern Med. 1999 Dec 7;131(11):834-7. doi: 10.7326/0003-4819-131-11-199912070-00006.


Background: Chlorhexidine is better than povidone-iodine for care of catheter sites, but it is not known whether chlorhexidine is superior in reducing blood culture contamination.

Objective: To determine whether alcoholic chlorhexidine is a more effective skin antiseptic for collection of blood cultures than aqueous povidone-iodine.

Design: Randomized, controlled trial.

Setting: Three adult intensive care units in a French university hospital.

Patients: 403 adults who had at least one blood culture drawn through a peripheral vein.

Interventions: Patients were randomly assigned to receive skin preparation with an aqueous solution of 10% povidone-iodine or an alcoholic solution of 0.5% chlorhexidine before phlebotomy.

Measurements: Contamination rates of blood cultures.

Results: Of 2041 blood cultures collected in 403 patients, 124 yielded pathogens. Chlorhexidine reduced the incidence of blood culture contamination more than povidone-iodine (14 of 1019 cultures [1.4%] compared with 34 of 1022 cultures [3.3%]; odds ratio, 0.40 [95% CI, 0.21 to 0.75]; P = 0.004).

Conclusion: Skin preparation with alcoholic chlorhexidine is more efficacious than skin preparation with aqueous povidone-iodine in reducing contamination of blood cultures.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Infective Agents, Local / administration & dosage*
  • Blood / microbiology
  • Blood Specimen Collection / methods*
  • Blood Specimen Collection / standards*
  • Chlorhexidine / administration & dosage*
  • Disinfectants / administration & dosage*
  • Humans
  • Povidone-Iodine / administration & dosage*
  • Prospective Studies
  • Time Factors


  • Anti-Infective Agents, Local
  • Disinfectants
  • Povidone-Iodine
  • Chlorhexidine